A conventional electrical connector includes a body having a plurality of receiving holes formed through the body, and a plurality of terminals respectively fixed in the receiving holes. The body is made of an insulating material.
Electromagnetic interference occurs among the terminals of the electrical connector during signal transmission. Especially with the development of digital products towards being thin, light and high-end, the volume of the electrical connector decreases accordingly, but increasingly more functions are demanded. Hence, as the volume of the body becomes smaller, and the number of terminals needs to remain unchanged or even be increased, it inevitably reduces the pitch between the terminals, and makes the electromagnetic interference problem worse.
Accordingly, another type of electrical connector has been proposed in this field, in which based on the above electrical connector, a metal layer is plated in each receiving hole, and then an insulating layer is plated on the metal layer. As metals can reflect, absorb and counteract electromagnetic waves, the metal layer may solve the problem of electromagnetic interference among terminals. The insulating layer is located between the terminal and the metal layer, and can prevent conduction between the two. Although the above electrical connector can prevent electromagnetic interference in some cases, the following problems still exist.
1. After the electrical connector is used for a long period of time, the metal layer and the insulating layer are easily aged, or if the metal layer and the insulating layer are plated poorly, the metal layer and the insulating layer are easily broken or even peel off. Once the metal layer and the insulating layer peel off, the electrical connector will lose the electromagnetic shielding function, or even may be damaged due to short circuit.
2. It is rather difficult to plate the metal layer in the narrow receiving hole. Generally, a liquid metal is enabled to flow from above the receiving hole into the receiving hole. In this case, as for the metal layer on the inner wall of the receiving hole, the upper part is thicker than the lower part, resulting in uneven thickness. To reduce the waste of metal materials, the electromagnetic shielding effect at the thin part of the metal layer is poor.
If the metal layer is brush-plated in the receiving hole, a brush needs to be inserted into the receiving hole for plating, but even thickness still cannot be ensured. Therefore, the problem that the electromagnetic shielding effect at the thin part of the metal layer is poor still exists.
3. To enable the electrical connector to achieve a shielding function, it is required to fabricate the body having the receiving holes in advance, plate the metal layer in the receiving hole, and then plate the insulating layer outside the metal layer. The process is complex.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.